package cn.lokei.gateway.service;

import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

import cn.lokei.gateway.entity.IotChannel;
import io.netty.channel.Channel;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.util.concurrent.GlobalEventExecutor;

@Component
public class ChannelSupervise implements ApplicationContextAware {

  private static ApplicationContext applicationContext; // Spring应用上下文环境

  // private ChannelGroup globalGroup = new
  // DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
  private ConcurrentMap<String, IotChannel> globalChannel = new ConcurrentHashMap<String, IotChannel>();
  private ConcurrentMap<String, ChannelGroup> subTopicMap = new ConcurrentHashMap<String, ChannelGroup>();
  /*
   * 实现了ApplicationContextAware 接口，必须实现该方法；
   * 通过传递applicationContext参数初始化成员变量applicationContext
   */
  @Override
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    ChannelSupervise.applicationContext = applicationContext;
  }

  public static ApplicationContext getApplicationContext() {
    return applicationContext;
  }

  @SuppressWarnings("unchecked")
  public static <T> T getBean(String name) throws BeansException {
    return (T) applicationContext.getBean(name);
  }

  public static <T> T getBean(Class<T> clazz) throws BeansException {
    return (T) applicationContext.getBean(clazz);
  }

  public void addChannel(Channel channel) {
    globalChannel.put(channel.id().asLongText(), new IotChannel(channel.id()));
  }

  public void removeChannel(Channel channel) {
    IotChannel iotChannel = this.globalChannel.get(channel.id().asLongText());
    Set<String> subTopics = iotChannel.getSubTopics();
    for (String topic : subTopics) {
      if(this.subTopicMap.get(topic).size() == 0) {
        this.subTopicMap.remove(topic);
      }
    }
    globalChannel.remove(channel.id().asLongText());
  }

  public IotChannel findChannel(String id) {
    return globalChannel.get(id);
  }

  public void subTopic(String topic, Channel channel) {
    ChannelGroup channelGroup = this.subTopicMap.get(topic);
    if(channelGroup == null) {
      channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
      this.subTopicMap.put(topic, channelGroup);
    }
    channelGroup.add(channel);
    IotChannel iotChannel = this.globalChannel.get(channel.id().asLongText());
    iotChannel.getSubTopics().add(topic);
  }

  public ChannelGroup subChannels(String topic) {
    return this.subTopicMap.get(topic);
  }

  public void unsubTopic(List<String> topics, Channel channel) {
    for (String topic : topics) {
      ChannelGroup channelGroup = this.subTopicMap.get(topic);
      if(channelGroup != null) {
        channelGroup.remove(channel);
        if(channelGroup.size() == 0) {
          this.subTopicMap.remove(topic);
        }
      }
    }
  }
}